A typical adjuster device for a deflector fitting of a vehicle occupant restraint system comprises a vehicle-fixed rail provided with latching openings and having a bottom part and two side parts, and a sled shiftable in the rail and coupled to a vehicle seat. The sled is provided with a fitting part for the deflector fitting and at least one latching part which is able to cooperate with the latching openings to block the sled against a downwards displacement in the rail relative to the vehicle.
By means of such an adjuster device the run of the seat belt may be optimally adapted to the stature of the vehicle occupant in each case, this adaptation being achieved via the fore and aft adjustment of the vehicle seat. The problem posed with such an adjuster device is that whilst, on the one hand, smooth adjustment of the sled upon fore and aft adjustment of the vehicle seat needs to be assured, on the other, the sled must be reliably blocked on the rail in any position when via the seat belt a force is exerted on the deflector fitting oriented downwards relative to the vehicle as is the case in an accident. This problem is aggravated when the vehicle occupant restraint system is provided with a belt tensioner which eliminates belt slack from the system in case of an accident. The forces thereby exerted on the deflector fitting may result in the latching part no longer reliably engaging the next available latching opening and thus the sled is displaced downwards relative to the vehicle, as a result of which the effect of the belt tensioner is impaired.